* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8f9fa;
    padding: 20px;
}

.firmware-selector {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    padding: 30px;
}

.header {
    text-align: center;
    margin-bottom: 30px;
}

.header h2 {
    color: #2c3e50;
    margin-bottom: 10px;
    font-size: 28px;
}

.header p {
    color: #7f8c8d;
    font-size: 16px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #2c3e50;
    font-size: 16px;
}

.help-text {
    font-size: 14px;
    color: #7f8c8d;
    margin-bottom: 10px;
    font-style: italic;
}

.dropdown-container {
    position: relative;
}

.dropdown-input {
    width: 100%;
    padding: 15px;
    border: 2px solid #e1e8ed;
    border-radius: 8px;
    font-size: 16px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.dropdown-input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.dropdown-input::placeholder {
    color: #bdc3c7;
}

.dropdown-list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 2px solid #e1e8ed;
    border-top: none;
    border-radius: 0 0 8px 8px;
    max-height: 200px;
    overflow-y: auto;
    z-index: 1000;
    display: none;
}

.dropdown-list.show {
    display: block;
}

.dropdown-item {
    padding: 12px 15px;
    cursor: pointer;
    border-bottom: 1px solid #f1f3f4;
    transition: background-color 0.2s ease;
}

.dropdown-item:hover {
    background-color: #f8f9fa;
}

.dropdown-item:last-child {
    border-bottom: none;
}

.dropdown-item.selected {
    background-color: #3498db;
    color: white;
}

.version-group {
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    display: none;
}

.version-group.show {
    opacity: 1;
    transform: translateY(0);
    display: block;
}

.version-select {
    width: 100%;
    padding: 15px;
    border: 2px solid #e1e8ed;
    border-radius: 8px;
    font-size: 16px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.version-select:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.download-section {
    text-align: center;
    margin-top: 30px;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.4s ease;
    display: none;
}

.download-section.show {
    opacity: 1;
    transform: translateY(0);
    display: block;
}

.download-btn {
    background: linear-gradient(135deg, #27ae60, #2ecc71);
    color: white;
    border: none;
    padding: 18px 40px;
    font-size: 18px;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(46, 204, 113, 0.3);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(46, 204, 113, 0.4);
}

.download-btn:active {
    transform: translateY(0);
}

.progress-indicator {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 20px;
}

.step {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: #e1e8ed;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: #7f8c8d;
    margin: 0 10px;
    transition: all 0.3s ease;
}

.step.active {
    background: #3498db;
    color: white;
}

.step.completed {
    background: #27ae60;
    color: white;
}

.step-connector {
    width: 40px;
    height: 2px;
    background: #e1e8ed;
    transition: all 0.3s ease;
}

.step-connector.completed {
    background: #27ae60;
}

.no-results {
    padding: 15px;
    text-align: center;
    color: #7f8c8d;
    font-style: italic;
}

.selected-layout {
    background: #e8f5e8;
    color: #27ae60;
    font-weight: 600;
    border-color: #27ae60;
}
